what a rapid reply- thanks Hans!

yes i just found many images online of this exact rust colour, so this must be the explanation. they are dramatic -and you couldn't wear them over a chiffon blouse...

Although, I have to admit, I own a 'bug bead', too, from a necklace I found years ago in a thrift shop. Shown on top of a framed print/book page I found at an antique store.

Do you stil have the other beads of the necklace? Maybe that can tell more were and when it was made!

Just some pale blue seed beads, and not quality ones at that.
I think it was made very recently.
But thanks for asking! :-)

i happen to have an example of one of these blue-grey "Chiton" external protective casings, ready prepared for attachment as a pendant or bead.= a marine mollusc with 8 overlapping dorsal shell plates ...

view of a pendant made of a pair of chiton shells shown joined edge-on...
and from above
(they look rather like a woodlouse)... actual length 1.4 inches, =30mm.
almost certainly from the Phillippines

From 2006:

http://beadcollector.net/cgi-bin/anyboard.cgi?fvp=/openforum/&cmd=iYz&aK=44885&iZz=44885&gV=0&kQz=&aO=1&iWz=0

thanks -a good link- and i thought i had a string of these big yellowy tube shapes also, but can't find them ...

hy Stefany, hereby two pictures of a fulgurite, or lightning tube.
it is not very visible in these pictures, taken with my former camera, but a thin layer on the inside of the perforation is completely molten glass. On the outside you can see the sintered sand grains with the typical bulges of searching the high voltage electric discharge its way in the ground.
this tube is app. 4 cm long.

dear Hans
it gets more interesting...
my rust-coloured lumpy beads and the yellowy sand-coloured beads that appear in some of the photos from 2006 that are shown in the BCN conversation link Jamey refers to- -i thought i had a strand of those but if i do i can't find them...
but if they have holes and can be threaded then even if the result is not jewellery, they still are exciting beads..worth studying .. from my point of view. termite work, caddis fly tubes or results of lightning strikes- -

or Hans can you definitely tell me they are something else?

Hi Stefany,
Don’t think this is fulgurite, or is there a more glassy inside?
Otherwise I think these are parts of the chimneys on termite hills by which the temperature inside the mound is regulated. So also made by termites like the other beads you showed before.

OK, they don't actually have glassy insides...
but ... then i still want to find out more...?
i want to see a real certified Fulgurite bead that shows the glassiness, and i also want to find out what my beads are and where they originated from- with their sandy yellow colour and strung on raffia in the african way-

i think i remember getting them in the tribal jewellery fair in Amsterdam a few years ago...

Hi Stefany,
Yes, I remember the dealer at the Duijf and have send him the picture.
He told me the chuncks were collected in Mali, near Mopti. It is a kind of clumped together iron sand (iron ore) and it was found around the roots of plants. So the perforation is left behind by the removed roots and some holes were reamed to be able to thread.
Afterwards I have never seen these kind of beads again.

hope the photos get through and are clear enough!
i show all the possible termite or thunderbolt or fulgurite beads that i possess-
the single black and white one does have a more glass-like surface on the inside. i got that a few years ago in Tucson. hope the image shows it.
any comments welcome...